Lens barrel assembly and camera including the same

ABSTRACT

A lens barrel assembly, a camera including the lens barrel assembly, and a method of assembling a lens barrel are disclosed. The lens barrel assembly is provided that includes an optical lens, a unitary barrel having an outlet slit defined therethrough, and a flexible printed circuit board extending through the outlet slit to communicate signals between an area inside the barrel and an area outside the barrel.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a continuation of U.S. Pat. No. 8,057,111 Ser. No.12/649,469 filed on Dec. 30, 2009, which claims the benefit of KoreanPatent Application No. 10-2008-0138535 filed on Dec. 31, 2008, in theKorean Intellectual Property Office, the entireties of which areincorporated herein by reference.

BACKGROUND

1. Field of the Invention

The invention relates to a lens barrel assembly and a camera includingthe lens barrel assembly. More particularly, the invention relates to alens barrel assembly having an improved extension structure forextending a flexible printed circuit board (FPCB) configured to transmitsignals between the inside and the outside of the lens barrel assembly,and a camera including the lens barrel assembly.

2. Description of the Related Art

Generally, a camera includes a lens barrel assembly and a camera body.The lens barrel assembly includes an optical lens installed in front ofthe camera body. The optical lens guides and forms an image of asubject. Also, a lens barrel including the optical lens is installedwithin in the lens barrel assembly. The lens barrel is driven along anoptical axis so as to perform a zooming operation. The lens barrelreceives a driving signal from the camera body via a FPCB.

The FPCB transmits signals between the inside and outside of the lensbarrel assembly. In this case, physical interference may be causedduring the zooming operation by extension portions that extend insidethe lens barrel assembly. This physical interference can thus causenoise and a driving error of a lens barrel assembly. Due to thedevelopment of an optical image stabilizing (OIS) correction operationfor correcting the adverse effects of a user's hand shaking while usingthe camera, the number of wires of the FPCB has increased, therebyincreasing the width of the FPCB. Accordingly, adverse effectsassociated with the above-discussed noise and driving error of a lensbarrel assembly FPCB have become more serious.

Generally, a separate fixing structure for fixing a FPCB to a lensbarrel assembly is utilized. This arrangement, however, increases thenumber of components and associated manufacturing costs. In addition,the fixing structure installed in the lens barrel assembly may limit theextent to which a camera including the lens barrel assembly can beminiaturized.

SUMMARY

The invention provides a lens barrel assembly having an improvedextension structure for extending a FPCB configured to transmit signalsbetween the inside and outside of the lens barrel assembly. Theinvention also provides a camera including the lens barrel assembly, anda method of assembling the lens barrel assembly.

According to an embodiment of the invention, a lens barrel assembly isprovided. The lens barrel assembly includes an optical lens, a unitarybarrel having an outlet slit defined therethrough, and a FPCB extendingthrough the outlet slit to communicate signals between an area insidethe barrel and an area outside the barrel.

The outlet slit may be defined along a circumferential direction of thebarrel case.

The barrel may also have an assembly slit defined therethrough, theassembly slit being connected to the outlet slit.

The assembly slit may connect to a front or rear edge of the barrel toallow the FPCB to slide into and across the assembly slit into theoutlet slit during assembly of the lens barrel assembly.

The lens barrel assembly may include a lens assembly installed andconfigured to move along an optical axis, wherein the optical lens isinstalled in the lens assembly.

An end of the FPCB may be connected to the lens assembly, and anotherend of the FPCB extend to the area outside the barrel.

A portion of the FPCB accommodated in the lens barrel assembly may havea length sufficient to accommodate the movement of the lens assembly.

The outlet slit may be away from any edge of the barrel.

An edge of the outlet slit may be a rounded curved surface.

The outlet slit may include a separation blocking stumbling projectionformed at an end of the outlet slit.

The FPCB may have a u-shaped fold corresponding to an edge of the outletslit.

According to another embodiment of the invention, a method of assemblinga lens barrel including a unitary barrel having an outlet slit andassembly slit defined therethrough, the assembly slit being connected tothe outlet slit is provided that includes sliding a FPCB into and acrossthe assembly slit into the outlet slit.

The method may include forming a u-shaped bend in the FPCB correspondingto an edge of the outlet slit, and engaging an edge of the FPCB with aseparation blocking stumbling projected formed at an end of the outletslit to retain the FPCB in the outlet slit.

The outlet slit may be defined along a circumferential direction of thebarrel away from any edge of the barrel, and the assembly slit mayconnect to an edge of the barrel to enable the FPCB to slide into theassembly slit.

The method may include installing a lens assembly including a lens, andcoupling an end of the FPCB to the lens assembly.

According to yet another embodiment of the invention, a camera isprovided that includes a camera body, a lens assembly comprising anoptical lens installed in the lens assembly and configured to move alongan optical axis, a barrel having an outlet slit defined therethrough,and a FPCB extending through the outlet slit to communicate signalsbetween the lens assembly and the camera body.

The outlet slit may be away from any edge of the barrel.

The barrel also may also have an assembly slit defined therethrough, theassembly slit being connected to the outlet slit, and the assembly slitconnecting to an edge of the barrel to allow the FPCB to slide into andacross the assembly slit into the outlet slit during assembly of thelens barrel assembly.

The FPCB may have a u-shaped fold corresponding to an edge of the outletslit.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the invention will becomemore apparent by describing in detail exemplary embodiments thereof withreference to the attached drawings in which:

FIGS. 1 through 3 are vertical cross-sectional views of examples of alens barrel assembly in various states, according to an embodiment ofthe invention;

FIG. 4 is a perspective view of an example of a guide barrel in which anoutlet slit is formed, according to an embodiment of the invention;

FIG. 5 is a perspective view illustrating an example of a state in whicha FPCB is installed using an outlet slit, according to an embodiment ofthe invention;

FIGS. 6 and 7 are perspective views illustrating examples of states inwhich a FPCB is installed, according to Comparative Examples 1 and 2;

FIG. 8 is a schematic perspective view of an example of a FPCBconfigured to transmit signals between a lens assembly and camera body,according to an embodiment of the invention;

FIG. 9 is a perspective view of an example of a guide barrel in which anoutlet slit is formed, according to another embodiment of the invention;and

FIG. 10 is an enlarged perspective view of an example of a main portionof the example of FIG. 9, according to an embodiment of the invention.

DETAILED DESCRIPTION

Hereinafter, a lens barrel assembly and a camera including the lensbarrel assembly will be described with regard to exemplary embodimentsof the invention with reference to the attached drawings. FIGS. 1through 3 are vertical cross-sectional views of examples of a lensbarrel assembly 200 in various states, according to an embodiment of theinvention. That is, FIG. 1 is a cross-sectional view of an example ofthe lens barrel assembly 200 in a state in which the lens barrelassembly 200 is retracted backward when a photographing operation is notbeing performed. FIGS. 2 and 3 are cross-sectional views of examples ofthe lens barrel assembly 200 in states in which the lens barrel assembly200 is controlled to be in a telephoto state and a wide-angle state,respectively, when the lens barrel assembly 200 is protruded forward.The lens barrel assembly 200 includes first through third lensassemblies L1, L2 and L3, and a photoelectric transformer 160, which areaccommodated in the barrel case 100.

The barrel case 100 includes a fixed barrel 120 that is fixed to acamera body. The barrel case also includes first and second movablebarrels 141 and 142 that extend out of the fixed barrel 120 when aphotographing operation is being performed. The fixed barrel 120 mayinclude, for example, a lens base 121 and a guide barrel 130 having acylindrical shape and disposed at an outermost portion of the lensbarrel assembly 200. The outermost portion is viewed, for example, in aradial direction of the lens barrel assembly 200.

The first movable barrel 141 is accommodated in the fixed barrel 120 andis movable in front and rear directions with respect to the fixed barrel120. The second movable barrel 142 is accommodated in the first movablebarrel 141 and is movable in the front and rear directions with respectto the first movable barrel 141. The first and second movable barrels141 and 142 move in the front direction so as to extend out of the fixedbarrel 120 when a photographing operation is being performed. Also, thefirst and second movable barrels 141 and 142 move in the rear directionso as to be accommodated in the fixed barrel 120 when a photographingoperation is not performed. The movement of the first and second movablebarrels 141 and 142 is guided by cam-followers 125 and 145. Thecam-followers 125 and 145 are provided on a cylindrical surface of thefixed barrel 120 and the first movable barrel 141. Also, thecam-followers 125 and 145 are provided on a cylindrical surface of thefirst movable barrel 141 and the second movable barrel 142.

The first through third lens assemblies L1, L2 and L3 may respectivelyinclude first through third optical lenses 101, 102 and 103, and firstthrough third fixers 111, 112 and 113 for respectively installing thefirst through third optical lenses 101, 102 and 103. At least one of thefirst through third lens assemblies L1, L2 and L3 may perform, forexample, zoom-in and zoom-out operations while moving in the front andrear directions along an optical axis ‘O’ so as to perform atransforming operation between the telephoto state and the wide-anglestate.

For example, the second lens assembly L2 may be connected to a drivingmotor (not shown) so as to move in the front and rear directions. Thatis, the second lens assembly L2 is inserted into a lead screw of adriving shaft 180 extending across an internal space of the lens barrelassembly 200. When an operational signal is applied to the driving motor(not shown), the driving shaft 180 connected to the same axle of thedriving motor rotates, and the second lens assembly L2 moves in thefront and rear directions along the lead screw having a spiral shape andformed on the driving shaft 180. As illustrated in the example of FIG.2, in the telephoto state, the second lens assembly L2 moves in thefront direction so as to be close to the first lens assembly L1. In thewide-angle state, the second lens assembly L2 moves in the reardirection so as to be close to the third lens assembly L3.

The second lens assembly L2 may perform, for example, a shake correctionoperation (that is, an optical image stabilizing (OIS) operation) forcorrecting a unwanted effects caused by a user's shaking of a camera bycontrolling a location of the second optical lens 102. For example, thesecond lens assembly L2 may fix a focal point location of a subject,which is focused on the photoelectric transformer 160, by moving thesecond optical lens 102 in a direction perpendicular to the optical axis‘O’ in proportion to the detected shake of the camera. To achieve this,an actuator (not shown) for moving the second optical lens 102 to atarget location may be installed close to the second optical lens 102.The actuator may include, for example, a voice coil motor (VCM). Theshake correction operation may be controlled by an OIS control signalreceived from the camera body. A shutter S for controlling the amount oflight exposed to the photoelectric transformer 160 may be installed inthe second lens assembly L2. An open/close operation of the shutter Smay be performed according to a shutter control signal received from thecamera body. A circuit board P for converting the OIS control signal andshutter control signal received from the camera body into appropriatedriving signals may be installed in the second lens assembly L2.

A FPCB 150 for transmitting signals between the second lens assembly L2and the camera body may be connected to the second lens assembly L2, forexample, to the circuit board P of the second lens assembly L2. The FPCB150 may transmit, for example, the OIS control signal and the shuttercontrol signal, which control the shake correction operation, betweenthe camera body and the second lens assembly L2.

As illustrated in the examples of FIGS. 1 through 3, the FPCB 150 may beflexibly deformed according to the movement of the second lens assemblyL2 connected to an end of the FPCB 150 or a protruding/retractingoperation of the lens barrel assembly 200, and it maintains a stableconnection to the second lens assembly L2. In addition, the FPCB 150 mayhave a length sufficient to correspond to a variable location of thesecond lens assembly L2.

As illustrated in the example of FIG. 1, the FPCB 150 extends out of thebarrel case 100 from the second lens assembly L2 through an outlet slit135 that is formed in the guide barrel 130. One end of the FPCB 150 isconnected to a main circuit board (not shown) installed within thecamera body. The outlet slit 135 may be formed away from the rear of thebarrel case 100. For example, the outlet slit 135 may be formed awayfrom the lens base 121 covering the rear of the barrel case 100 in thefront direction. The FPCB 150 connected to the second lens assembly L2extends towards the guide barrel 130 via the rear of the barrel case 100and along an inner surface of the lens base 121. The FPCB 150 extendingin the front direction along an inner surface of the guide barrel 130extends out of the barrel case 100, and is then folded around the outletslit 135 so as to surround the guide barrel 130 and extend in the reardirection.

As described above, the length of the FPCB 150 may be sufficient tocorrespond to the variable location of the second lens assembly L2. As aresult, the FPCB 150 may correspond to a variable location of the secondlens assembly L2 by folding or unfolding a portion 150 a extending alongthe inner surface of the guide barrel 130 according to the variablelocation of the second lens assembly L2 while the FPCB 150 is nearlypivoted in the outlet slit 135.

Referring to the example of FIG. 2, when the second lens assembly L2moves in the front direction, the portion 150 a of the FPCB 150extending along the inner surface of the guide barrel 130 is unfolded asthe FPCB 150 is drawn by the second lens assembly L2. Then, referring tothe example of FIG. 3, when the second lens assembly L2 moves in therear direction, the portion 150 a of the FPCB 150 is closely adhered tothe inner surface of the guide barrel 130 by a self-elastic force of theFPCB 150 while the FPCB 150 that is previously unfolded is folded in a‘U’ shape.

The lens barrel assembly 200 illustrated in the examples of FIGS. 1through 3 may be assembled with the camera body (not shown) so as toconstitute the camera. As illustrated in the examples of FIGS. 1 through3, the lens barrel assembly 200 includes the photoelectric transformer160 converting an image of a subject into an electric image signal, andthe first through third lens assemblies L1, L2 and L3 for forming animage of the subject on the photoelectric transformer 160. The camerabody may include circuit structures for processing the electrical imagesignal transmitted from the lens barrel assembly 200, that is, from thephotoelectric transformer 160 and storing the electrical image signal inan appropriate file format.

FIG. 4 is a perspective view of an example of a guide barrel 130 inwhich the outlet slit 135 is formed, according to an embodiment of theinvention. FIG. 5 is a perspective view illustrating an example of astate in which the FPCB 150 is installed using the outlet slit 135,according to an embodiment of the invention. The outlet slit 135 may beformed in the guide barrel 130 along a circumferential direction thereofso as to have a first length D1. The first length D1 of the outlet slit135 may correspond to the width of the FPCB 150, and may be sufficientlylarge to prevent physical interference between the FPCB 150 and edges ofthe outlet slit 135, for example. However, the outlet slit 135 isdesigned to have a size, that is, the first length D1, just slightlygreater than the width of the FPCB 150, for example, thereby preventingan exposure of external light to the inside of the guide barrel 130,that is, the inside of the lens barrel assembly 200. This also preventsthe penetration of external foreign substances from moving inside of thelens barrel assembly 200.

An assembly slit 133 together with the outlet slit 135 may be formed,for example, in the guide barrel 130. The assembly slit 133 may beformed in the front and rear direction of the guide barrel 130 so as tohave a second length D2. Also, the assembly slit 133 may extend from therear of the guide barrel 130 to the outlet slit 135 towards the front ofthe guide barrel 130. Referring to the example of FIG. 4, the assemblyslit 133 may be opened towards the rear of the guide barrel 130.Alternatively, the assembly slit may be opened towards the front of theguide barrel 130, and may be formed in the guide barrel 130 in the frontand rear directions from an opening 130′ to the outlet slit 135.

When both ends of the FPCB 150 are respectively connected to the secondlens assembly L2 and the main circuit board (not shown), an intermediateportion of the FPCB 150 may be fixed to the guide barrel 130 via theopening 130′ of the assembly slit 133. The portion of the FPCB 150 fixedto the guide barrel 130 may be guided along the assembly slit 133 so asto be accommodated in the outlet slit 135.

For example, the assembly slit 133 and the outlet slit 135 may bevertically bent as a whole, wherein ends of the assembly slit 133 andthe outlet slit 135 are connected to each other. A cutting portion 131that is surrounded by the assembly and outlet slits 133 and 135 so as tobe cut from the guide barrel 130 may support the portion of the FPCB 150that extends out of the barrel case 100 through the outlet slit 135, forexample.

Referring to the example of FIG. 5, the FPCB 150 extending out of thebarrel case 100 through the outlet slit 135 is supported by the cuttingportion 131, extending in the rear direction, is folded around the rearof the barrel case 100, and then extends in the front direction, so asto have a ‘U’ shape, for example.

In the examples of FIGS. 4 and 5, the outlet slit 135 and the assemblyslit 133 are formed in the guide barrel 130, but are not limited to suchan arrangement. For example, the outlet slit 135 and the assembly slit133 may be formed in any portion of the barrel case 100 as long as theFPCB 150 extends out of the barrel case 100, for example.

FIGS. 6 and 7 are perspective views illustrating examples of states inwhich a FPCB 50 is installed, according to Comparative Examples 1 and 2,respectively. Referring to the examples of FIGS. 6 and 7, press formingmaterials 40 and 40′ for supporting the FPCB 50 are disposed in lensbarrel assemblies 30 and 30′, respectively. As illustrated in theexample of FIG. 6, the FPCB 50 is folded along the press formingmaterial 40 in a ‘∩’ shape, and extends out of the lens barrel assembly30 via the rear of the lens barrel assembly 30. The FPCB 50 is foldedalong the press forming material 40 so as to correspond to a variablelocation of a lens assembly. In Comparative Examples 1 and 2, it isnecessary to manufacture and assemble the press forming materials 40 and40′ for supporting the FPCB 50, and the press forming materials 40 and40′ are installed in the lens barrel assemblies 30 and 30′, therebycausing physical interference between the press forming materials 40 and40′ and movable members such as a lens assembly, and also causing noisedue to the physical interference. In addition, when a moving axis isdistorted, or an error arises in terms of locations of the press formingmaterials 40 and 40′, both the resulting physical interference and theresulting noise may become more serious. In particular, along with theuser's requirements for small-sized barrels, interference due to thepress forming materials 40 and 40′ may also become more serious.

The FPCB 150 is supported by forming the outlet slit 135 in the lensbarrel assembly 200, in other words, in the guide barrel 130 of the lensbarrel assembly 200, as illustrated in the example of FIG. 4.Accordingly, manufacturing costs may be reduced by as much as thoserequired to manufacture the press forming materials 40 and 40′. Anassembly process for the press forming materials 40 and 40′ may beomitted. As a result, the associated assembly costs may decrease. Inaddition, in the example of FIG. 4, there is no noise and physicalinterference between the press forming materials 40 and 40′ andsurrounding members.

FIG. 8 is a schematic perspective view of an example of the FPCB 150 ofFIGS. 1 through 3, according to an embodiment. The FPCB 150 extends inan ‘A’ direction towards the second lens assembly L2, and it extends ina ‘B’ direction towards the main circuit board of the camera body. TheFPCB 150 may thus transmit the OIS control signal for controlling theshake correction operation and the shutter control signal forcontrolling the open/close operation of the shutter S between the camerabody and the second lens assembly L2, for example. The FPCB 150 includesa plurality of signal patterns (not shown) for transmitting therespective different control signals. A contact portion 155 of the FPCB150 having an electrical contact point with respect to the main circuitboard is formed so as to have a wide width W so that the signal patternshave a sufficient pitch.

If the size, that is, the first length D1, of the outlet slit 135 isincreased in order to correspond to the width W of the contact portion155, light leakage and penetration of external foreign substances mayoccur. As illustrated in the example of FIG. 4, by forming the assemblyslit 133 in the lens barrel assembly 200, that is, in the guide barrel130 of the lens barrel assembly 200, the intermediate portion of theFPCB 150 may be fixed to the lens barrel assembly 200, that is, to theguide barrel 130 of the lens barrel assembly 200 without regard to thewidth W of the contact portion 155. The assembly slit 133 may facilitateassembly of the FPCB 150 including the contact portion 155 having thewidth W.

FIG. 9 is a perspective view of a guide barrel 330 in which an outletslit 335 is formed, according to another embodiment of the invention.Referring to the example of FIG. 9, the outlet slit 335 for extendingthe FPCB 150 out of a barrel case is formed in the guide barrel 330along a circumferential direction thereof. An assembly slit 333 isformed in the guide barrel 330 in the front and rear directions andextends towards the outlet slit 335.

FIG. 10 is an enlarged perspective view of an example of a main portionof the example of FIG. 9, according to an embodiment of the invention.Referring to the example of FIG. 10, a separation blocking stumblingprojection 338 for blocking separation of the FPCB 150 is formed at anopen end of the outlet slit 335. The separation blocking stumblingprojection 338 may protrude from an inner surface of the outlet slit 335to the inside of the outlet slit 335. The separation blocking stumblingprojection 338 may fix an assembly location of the FPCB 150 supported bythe outlet slit 335, for example.

When the FPCB 150 supported by the outlet slit 335 comes into contactwith the inner surface of the outlet slit 335, physical interferencesuch as friction may occur due to a contact portion between the FPCB 150and the inner surface of the outlet slit 335, for example. By forming arounded curved surface R at an edge of the inner surface of the outletslit 335, damage to the FPCB 150 due to the friction may be minimized.

According to the invention, noise and driving error of a lens barrelassembly may be minimized by improving an extension structure forextending a FPCB configured to transmit signals between the inside andoutside of a lens barrel assembly.

In addition, because a separate assembly structure for fixing the FPCBto the lens barrel assembly is not required, the overall number ofcomponents and associated manufacturing costs may be reduced. Inaddition, a lens barrel assembly that is appropriate for a small-sizedcamera may be provided.

While the invention has been particularly shown and described withreference to exemplary embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the invention as defined by the following claims.

1. A lens barrel assembly comprising: an optical lens; a barrel having an outlet slit and an assembly slit, one end of the assembly slit being connected to the outlet slit; and a flexible printed circuit board extending through the outlet slit to communicate signals between an area inside the barrel and an area outside the barrel; wherein the outlet slit is away from any edge of the barrel, and the other end of the assembly slit is connected to an edge of the barrel to be opened.
 2. The lens barrel assembly of claim 1, wherein the outlet slit is defined along a circumferential direction of the barrel.
 3. The lens barrel assembly of claim 1, wherein the assembly slit is connected to the edge of the barrel to allow the flexible printed circuit board to slide into and across the assembly slit into the outlet slit during assembly of the lens barrel assembly.
 4. The lens barrel assembly of claim 1, further comprising a lens assembly installed and configured to move along an optical axis, wherein the optical lens is installed in the lens assembly.
 5. The lens barrel assembly of claim 4, wherein an end of the flexible printed circuit board is connected to the lens assembly, and another end of the flexible printed circuit board extends to the area outside the barrel.
 6. The lens barrel assembly of claim 4, wherein a portion of the flexible printed circuit board accommodated in the lens barrel assembly has a length that is sufficient to accommodate the movement of the lens assembly.
 7. The lens barrel assembly of claim 1, wherein the outlet slit is away from any edge of the barrel.
 8. The lens barrel assembly of claim 1, wherein an edge of the outlet slit is a rounded curved surface.
 9. The lens barrel assembly of claim 1, further comprising a separation blocking stumbling projection formed at an end of the outlet slit.
 10. The lens barrel assembly of claim 1, wherein the flexible printed circuit board has a u-shaped fold corresponding to an edge of the outlet slit.
 11. A method of assembling a lens barrel including a barrel having an outlet slit and assembly slit, one end of the assembly slit being connected to the outlet slit, the method comprising: sliding a flexible printed circuit board into and across the assembly slit into the outlet slit, wherein the outlet slit is defined away from any edge of the barrel, and the other end of the assembly slit is connected to an edge of the barrel to be opened.
 12. The method of claim 11, further comprising: forming a u-shaped bend in the flexible printed circuit board corresponding to an edge of the outlet slit; and engaging an edge of the flexible printed circuit board with a separation blocking stumbling projection formed at an end of the outlet slit to retain the flexible printed circuit board in the outlet slit.
 13. The method of claim 11, wherein the outlet slit is defined along a circumferential direction of the barrel and the assembly slit connects to the edge of the barrel to enable the flexible printed circuit board to slide into the assembly slit.
 14. The method of claim 11, further comprising: installing a lens assembly including a lens; and coupling an end of the flexible printed circuit board to the lens assembly.
 15. A camera comprising: a camera body; a lens assembly comprising an optical lens installed in the lens assembly and configured to move along an optical axis; a barrel having an outlet slit and an assembly slit, one end of the assembly slit being connected to the outlet slit; and a flexible printed circuit board extending through the outlet slit to communicate signals between the lens assembly and the camera body; wherein the outlet slit is away from any edge of the barrel; and the other end of the assembly slit is connected to an edge of the barrel to be opened.
 16. The camera of claim 15, wherein the assembly slit is connected to the edge of the barrel to allow the flexible printed circuit board to slide into and across the assembly slit into the outlet slit during assembly of the lens barrel assembly.
 17. The camera of claim 15, wherein the flexible printed circuit board has a u-shaped fold corresponding to an edge of the outlet slit. 